Lift truck



Ap 1954 A. J. MERCIER ET AL LIFT TRUCK Filed May 11, 1950 INVENTORS A7706 J/Izncmy mm Patented Apr. 13, 1954 2,675,13 9 LIFT TRUCK Amos J. Mercier, Holyoke, and George G.

Morin,

South Hadley Falls, Mass. Application May 11, 1950, Serial No. 161,372 8 Claims. (01. 214620) This invention relates to improvements in power lift trucks and more particularly to the means for picking up, carrying, and depositing loads of articles as the truck is used to handle such loads in industrial plants, warehouses and the like.

The principal object of the invention is to provide a lift truck characterized by versatility and increased maneuverability in handling materials.

Another object is to provide in an article handling lift truck a structure by which the load supporting and carrying member thereof may be readily coupled to and uncoupled from the truck proper.

A further object of the invention is to provide a lift truck of the class described which is readily convertible for handling loads of articles of varying characters.

Another object is to provide resiliently mounted coupling means on such a truck, whereby the load carrying members of the truck may be quickly and easily coupled to the truck, without the use of the human hand.

Yet another object is to provide in a lift truck, interchangeable load carrying members which are easy to handle, inexpensive to manufacture, and which are especially useful for handling many types of materials, whether packaged in a unitary bundle or left free in the form of a plurality of discrete or granular articles.

These and other objects and advantages of the invention will be fully developed in the following specification read in connection with the accompanying drawings, in which:

Fig. 1 is a perspective view of a power lift truck embodying the present invention;

Figs. 2, 3, and 4 are fragmentary side elevational views showing successive steps in the manipulation of the truck in coupling the load carrying element of the combination to the elevator element;

Fig. 5 is a fragmentary perspective view show ing an alternative arrangement;

Fig. 6 is a perspective view of an alternative form of intermediate coupling member;

Fig. 7 is a perspective view showing an alternative form of the load carrying element; and

Fig. 8 is a fragmentary perspective view showing a further adaptation of the truck to a different type of load supporting means.

Fig. 1 shows a lift truck in which is mounted an elevating means, indicated generally at I, which in the form illustrated includes an upright channel 2 pivotally attached to the front of the truck by a pair of rotatable braces 3 (only one of which is seen in Fig. 1), and a second channel 4 shown telescoped in the channel 2 and adapted to be extended upwardly therefrom by means of a hydraulic ram indicated at 5. The elevating mechanism also includes a pair of chains 6. The details of construction and operation of parts just described are well known and need not be further described here. It will be understood that any suitable elevating means may be employed.

A frame 7 is connected to the lower ends of the chains 6 and includes a pair of vertically disposed elements 8 and a pair of horizontally disposed elements 9. It will be noted that end portions 18 of the horizontal elements 9 extend laterally beyond the vertical elements 8.

Intermediate coupling members ll including rigid straps l2 are adapted, by the provision of rearwardly offset hooks l3 at their upper end portions, to be removably and pivotally hung in spaced relation along the uppermost horizontal frame member 9. Bolts I 4 threaded into the frame element 9 are received loosely in elongated openings I5 at the top portion of hooks l3 to anchor the coupling members to the frame 1. It will be understood that any convenient number of coupling members ll may be provided on the frame element 9. In the example illustrated by Fig. 1, three such members are provided. Two of them are shown supported on the lateral extensions H) of frame element 9. Each strap 12 is provided, on the side thereof remote from the truck proper, with a forwardly offset hookshaped receiver It. For a purpose to be described later, each coupling member II is preferably provided, on its back side, adjacent the truck, with a relatively light leaf spring I! which is anchored to the strap l2 at I8 and which extends rearwardly and downwardly from the body thereof to engage the front surface of the lowermost member Q of frame 1. As is shown best by Fig. 3, the spring I! serves to hold the lowermost portion of a coupling member I I spaced resiliently from the frame I.

In accordance with the invention the load carrying element of the truck takes the form of a load carrying float, indicated generally at IS, with which the receivers l6 are designed to cooperate by way of releasably coupling a load of articles to the frame 1. The float includes a generally flat article supporting bed portion 20 and an upstanding flange 2| across the rear end edge of the bed. The means for coupling the float to the coupling members II! is located at the top edge of the flange 2i and comprises a rearwardly and downwardly extending hook portion 22 along the upper edge of the flange. The hook formed by portion 22 opens downwardly at the rear of the float and is adapted to be engaged by the receivers l6 upon upward movement of the elevating means.

The bed portion 20 of the float l9 may take any desired form. The bed portion 20 shown by Fig. 1 is provided with longitudinal slots 23 cut therein. This form of the float i9 is adapted for use in loading and unloading truck trailers and freight cars, the floors of which are sometimes provided with spaced risers. The slots 23 accommodate such risers, so that the body of the bed portion 28 may be inserted under a load, between the same and the floor of the car or trailer. Fig. shows a float with its bed portion 26 corrugated longitudinally for added rigidity.

Figs. 2 through 4 illustrate the manner in which a load may be picked up by the lift truck for handling. The load of articles is positioned on'the bed of the floatv is resting on a floor or otherfirm supporting surface represented by the line s. The lift truck is driven forwardly, with its elevator positioned so that the upper and lower extremities of the receivers 16 and hook portion 22 respectively will clear each other, as in Fig. 2. It will be appreciated that, because of the resilient spacing provided between members H and the truck by springs ll, the. truck need not be precisely in line with the rear flange 2| and hook portion 22 of the float. The'coupling members H with their receivers 18 will, when the truck is maneuvered forwardly to bring them into engagement with flange 2| of the float, adjust themselves resiliently to such angular misalignment as. may exist between the truck and the rear of the float, by the action of springs ll. When this adjustment has been effected (the relation of the parts in adjusted condition is shown by Fig. 3), the elevator may be actuated to raise the frame l and coupling members H to bring the receivers 16. into engagement with the hooks formed by portions 22 on the float. Fig. 4 illustrates the hook. portion 22 engaged by receivers [6, with the float 19 supporting the load of articles raised slightly on the floor surface s. The process may be reversed to uncouple the. load from the lift, truck.

Having picked up. the loaded float. as described, the truck proceeds. to its destination where the loaded float is lowered until. it rests on the floor after which the float is uncoupled by further downward movement of the elevator. The loaded float may be deposited on top of the load of a previously deposited float to form piles and tiers in a warehouse, a freightv car or road truck, the floats remaining with their load. When the material is to be re-handled, as in removing from the warehouse to a freight car or road truck or vice versa, it is only necessary to bring the lift truck into. coupling position, raise the elevator to make the coupling, and proceed to trans port the loaded float to its new destination. Because no pallet is involved and because the floats occupy only a negligible space. the floats may be left with the load without materially decreasing the load capacity of the freight car or roadtruck. Similarly in warehouses the floats may be left with their loads without substantial decrease in the storage capacity and in fact storage capacity is increased by the invention since the greater maneuverability provided permits narrower aisles.

t will be recognized that. when the load is uncoupled, the length of the lift truck is reduced by the length of the forwardly extending float. The truck is able to be turned in a smaller area and so is useful in many places where conventional trucks cannot operate. On the other hand, a conventional fork lift truck of the type in wide use today for a material handling device is not materially shortened by unloading. The forwardly extending forks of such a truck are fixed on the front end of the same and may be used to pick up a load on a so-called pallet. To pick up a pallet, the fork truck must be maneuvered to insert the forks under the load surfaces of the pallet; to deposit a load, the truck must be backed from the pallet a distance equal to the length of the forks. And even when the truck is unloaded, the forks remain on the truck to hamper its maneuverability in restricted areas and so to limit its utility. The great maneuverability and increased utility of the truck of the invention, not onl when the truck is unloaded, but also when it is taking on or depositing a load of articles on the float, rep-resent amaior advance in the art of material handling. Goods may be warehoused and shipped on the floats for quick and economical handling, where the space consuming pallets of the prior practice prohibit such handling. 7

Fig. 6 shows an alternative form of intermediate coupling member for use in the structure described above. Essentially, the example of this figure comprises the three coupling members H joined together to provide a continuous plate 24 having three hooks 25 at the top thereof and a hook-shaped receiver 26 extending along its lower edge.

In Fig. 7 a rigid back plate 21 is shown mounted directly on the elevator of a lift truck. An upwardly facing forwardly offset hook-shaped receiver 28 is fixed along the lower edge of the plate 2'! to engage and secure the hook portion 22 of a float l9. Fig. '7 also illustrates an al.- ternative form of float having a bed portion 20 provided with side walls 29. This type of float is especially useful in handling unpackaged material,. such as coal and the like, which is left free in the form of discrete or granular articles.

Under some conditions a load supporting and carrying. means in the form of the conventional forks may at times be desirable. Fig- 8 provides an illustration of the fact thatv the truck of the present invention may be converted for fork operation simply by removing the. coupling members H from the frame land replacingv them with angular fork members 30 having upwardly extending portions SI of substantially the same length as the replaced coupling members. The bolts M which anchored the. coupling members II in place may be used to secure the modified forks 3% on the frame I.

It will now be appreciated that the invention of which the foregoing examples are embodiments presents a novel. contribution, of. great utility, to the material handling art. As far as we are aware, the most convenient. mode of handling bulky and heavy loads heretofore has been to employ a so-called pallet in connection with a fork lift truck. This mode of handling is characterized by the fact that it. is necessary, in order to pick up a palletized' load, to maneuver the truck so that its forks are inserted. properly in the pallet; to deposit the load, it is necessary either to withdraw the forksv from the pallet or to unload the pallet. By using the truck of this invention, with its float and spring-mounted '5 coupling members," all'that is required to pick up a load is to maneuver the truck into position against a pre-loaded float and raise the elevator.

To deposit a load, a truck operator need only lower the elevator after the float has come to rest on a supporting surface until the coupling members are disengaged from the float. It is manifest that a substantial amount of time and effort is conserved in such an operation, as distinguished from an operation in which the old;

fork and pallet elements are used.

Moreover, if it is desired to use forks for any reason in connection with a lift truck, the spring mounted coupling members may be readily removed, and forks such as those described and shown by Fig. 8 may be mounted upon the truck elevator.' This interchangeability affords a flexibility in the use of a single lift truck which has not heretofore been possible, with the result that greater utility may now be obtained from the same or a smaller number of material handling units.

A novel structure has thus been provided which will effect substanital economies in a wide variety of industrial and commercial operations.

What is claimed is:

1. A lift truck having elevating means at its forward end, an elevator member fixed to said means and having a substanitally plane surface parallel to the plane of movement of the elevating means, a load supporting member having a horizontal load supporting portion and provided at the rear edge of said portion with an upwardly extending flange, said flange terminating in a rearwardly and downwardly extending hook portion, and an intermediate coupling member removably and resiliently connected at its upper end to said elevating member and provided at its lower end with a forwardly and upwardly extending hook-shaped receiver, whereby said flange and said elevator means may be releasably coupled together upon interengagement of said hook portion and said receiver.

2. A lift truck having elevating means at the front thereof, a frame connected to said elevating means, a plurality of intermediate coupling members removably mounted in laterally spaced and aligned relation on said frame, a spring between each of said members and said frame whereby the members are held resiliently spaced from the frame, a hook-shaped receiver on each of said members, and a load supporting float comprising a flat bed portion having a hook at its rear edge, said hook being complementary to said receivers, whereby upon resilient engagement of said hook by said receivers and elevation of said elevating means said float is releasably coupled to said elevating means.

3. In a power lift truck equipped with elevating means for carrying material on load supporting floats which have coupling means positioned rearwardly of their load supporting beds adapted to be coupled to and uncoupled from said truck upon raising and lowering the elevating means thereof, a plurality of coupling members removably connected to said elevating means, a spring between each of said members and said elevating means whereby the members are normally held resiliently spaced from the elevating means, and a forwardly offset and upwardly extending hookshaped receiver on each of said coupling members.

4. A load supporting float for use in connection with a power lift truck having a coupling member on the elevating means thereof, said float comprising a substantially flat horizontal bed portion, and having an integral short upwardly extending flange along the rear edge thereof, the upper edge portion of said flange being bent rearwardly and downwardly to form a coupling member positioned at the rear of the float and engageable with and disengageable from said first-named coupling member upon relative movement of the coupling members.

5. A load coupling member comprising a rigid strap having means at its upper end for releasably connecting the same to the elevating means of a lift truck for limited pivotal movement and an upwardly opening hook at its lower end for releasably coupling the same to a load supporting float, and a leaf spring mounted upon said strap on the side thereof adjacent said elevating means and engaging therewith to hold said strap outwardly and downwardly inclined with respect to said elevating means when said hook is uncoupled from a float, said spring being yieldable to bring the strap into substantially face to face engagement with said elevating means when said hook is coupled to a float.

6. A lift truck having elevating means at its forward end, an elevator member fixed to said means for movement therewith, a load supporting member having a horizontal load supporting portion formed with an integral vertical flange along its rear edge, the upper edge portion of said flange being bent rearwardly and downwardly to form a downwardly opening hook, means for releasably coupling said load supporting member to said elevator member comprising a plurality of transversely spaced intermediate coupling members connected at their upper ends to the upper edge of said elevator member and extending downwardly substantially to the lower edge of said elevator member, the lower ends of said intermediate members being provided with forwardly and upwardly extending coupling members engaging between said flange and said downwardly and rearwardly bent edge portion thereof to releasably couple said load supporting member to the elevating member along the lower edge thereof.

'7. A lift truck having elevating means at its forward end, an elevator member fixed to said means for movement therewith, a load supporting member having a horizontal load supporting portion formed with an integral vertical flange along its rear edge, the upper edge portion of said flange being bent rearwardly and downwardly to form a downwardly opening hook, means for releasably coupling said load supporting member to said elevator member comprising a plurality of transversely spaced intermediate coupling members each independently and resiliently connected to said elevator member, forwardly and upwardly extending coupling members carried by said intermediate coupling members engageable between said flange and said downwardly and rearwardly bent edge portion thereof to releasably couple said load. supporting member to the elevating member.

8. A lift truck having elevating means at its forward end, an elevator member fixed to said means for movement therewith, a load supporting member having a horizontal load supporting portion formed with an integral vertical flange along its rear edge, the upper edge portion of said flange being bent rearwardly and downwardly to form a downwardly opening hook, means for releasably coupling said load supporting member to said elevator member comprising coupling memberspivotally comaected at their upper endsto the elevator member, the lower ends of said intermediate coupling" members tending coupling members engageable between said flange and said downwardly and rearwardly bent edge portion thereof toreleasably couple said lead supporting member to the elevating member, and; springs between each intermediate coupling member and the elevating member to permit independent movement of each intermediate coupling member and the'coupling member carried thereby as the. latter are moved into coupling engagement with the load supporting member.

References Cited the file of this patent UNITED STATES PATENTS Number Name H Date Carroll Dec. 9, 1924 Abbe 1 Sept. 27,1932 Cochran Feb. 3, 1942 Hazen May 1-8, 1943 Ulinski Jan. 11, 1944 Dunham -1 Jan. 30, 1945 Clapp an-.. Oct. 30, 1945 Stokes 1 Dec. 31, 1946 Britton May 18, 1 948 in... Mar. .22 .1949 Cirillo ..s....- Aug. 1, 1350 Dickson 1 Jan. 23, 1951 Cushman n Jan. 8, 1952 Turner Aug. 26, .1952 

